At the dawn of mankind, a colony of peaceful vegetarian apes awakens to find a glowing black monolith standing in their midst. After tentatively reaching out to touch the mysterious object, the apes become carnivores, with enough intelligence to employ bones for weapons and tools. Four million years later, in the year 2001, Dr. Heywood Floyd, an American scientist, travels to the moon to investigate a monolith that has been discovered below the lunar surface. Knowing only that the slab emits a deafening sound directed toward the planet Jupiter, the United States sends a huge spaceship, the Discovery , on a 9-month, half billion-mile journey to the distant planet. Aboard are astronauts David Bowman and Frank Poole, plus three others in frozen hibernation, and a computer called Hal 9000. During the voyage, Hal predicts the failure of a component on one of the spacecraft's antennae. Bowman leaves the ship in a one-man space pod to replace the crucial part; the prediction proves incorrect, however, and when Poole ventures out to replace the original part, Hal severs his lifeline. Bowman goes to rescue him, but Hal closes the pod entry doors and terminates the life functions of the three hibernating astronauts. Forced to abandon Poole, who is already dead, Bowman reenters the Discovery through the emergency hatch and reduces Hal to manual control by performing a mechanical lobotomy on the computer's logic and memory circuits. Now alone, Bowman continues his flight until he encounters a third monolith among Jupiter's moons. Suddenly hurtled into a new dimension of time and space, he is swept into a maelstrom of swirling colors, erupting landscapes and exploding galaxies. At last coming to rest in a pale green bedroom, Bowman emerges from the nonfunctioning space capsule. A witness to the final stages of his life, the withered Bowman looks up from his deathbed at the giant black monolith standing in the center of the room. As he reaches toward it, he is perhaps reborn, perhaps evolved, perhaps transcended, into a new "child of the universe," a fetus floating above the Earth.

"Gayaneh Ballet Suite," music by Aram Khatchaturian, performed by the Leningrad Philharmonic Orchestra, conductor Gennadi Rozhdestvensky, courtesy Deutsche Grammophon; "Atmospheres," music by György Ligeti, performed by the Southwest German Radio Orchestra, Conductor Ernest Bour; "Lux Aeterna," music by György Ligeti, performed by the Stuttgart Schola Cantorum, Conductor Clytus Gottwald; "Requiem," music by György Ligeti, performed by the Bavarian Radio Orchestra, Conductor Francis Travis; "The Blue Danube," music by Johann Strauss II, performed by the Berlin Philharmonic Orchestra, Conductor Herbert von Karajan, courtesy Deutsche Grammophon; Thus Spake Zarathustra , music by Richard Strauss, performed by the Berlin Philharmonic Orchestra, Conductor Karl Boehm.

Following the film's title in the opening credits is a title card reading: "The Dawn of Man." Stanley Kubrick's onscreen credit reads: "This film was directed and produced by Stanley Kubrick." 2001: A Space Odyssey opened in London in May 1968 with a running time of 141 minutes. The film was presented in Cinerama for roadshow engagements. According to the 1 May 1968 Filmfacts review, after the film's initial American release in New York, Washington D.C. and Boston, Kubrick edited 19 minutes. Filmfacts also noted that Martin Balsam, who originally played the voice of "Hal 9000," was replaced by Douglas Rain.
Kubrick won the Special Visual Effects Academy Award. The film was nominated for Academy Awards in Art Direction, Directing and Writing (Story and Screenplay). 2001: A Space Odyssey was ranked 15th on AFI's 2007 100 Years...100 Movies--10th Anniversary Edition list of the greatest American films, moving up from the 22nd position it held on AFI's 1997 list.